Improve pruning in greedy_search by sorting tables during search

MDEV-28073 Slow query performance in MariaDB when using many tables

The faster we can find a good query plan, the more options we have for
finding and pruning (ignoring) bad plans.

This patch adds sorting of plans to best_extension_by_limited_search().
The plans, from best_access_path() are sorted according to the numbers
of found rows.  This allows us to faster find 'good tables' and we are
thus able to eliminate 'bad plans' faster.

One side effect of this patch is that if two tables have equal cost,
the table that which was used earlier in the query is preferred.
This allows users to improve plans by reordering eq_ref tables in the
order they would like them to be uses.

Result changes caused by the patch:
- Traces are different as now we print the cost for using tables before
  we start considering them in the plan.
- Table order are changed for some plans. In most cases this is because
  the plans are equal and tables are in this case sorted according to
  their usage in the original query.
- A few plans was changed as the optimizer was able to find a better
  plan (that was pruned by the original code).

Other things:

- Added a new statistic variable: "optimizer_join_prefixes_check_calls",
  which counts number of calls to best_extension_by_limited_search().
  This can be used to check the prune efficiency in greedy_search().
- Added variable "JOIN_TAB::embedded_dependent" to be able to handle
  XX IN (SELECT..) in the greedy_optimizer.  The idea is that we
  should prune a table if any of the tables in embedded_dependent is
  not yet read.
- When using many tables in a query, there will be some additional
  memory usage as we need to pre-allocate table of
  table_count*table_count*sizeof(POSITION) objects (POSITION is 312
  bytes for now) to hold the pre-calculated best_access_path()
  information.  This memory usage is offset by the expected
  performance improvement when using many tables in a query.
- Removed the code from an earlier patch to keep the table order in
  join->best_ref in the original order.  This is not needed anymore as we
  are now sorting the tables for each best_extension_by_limited_search()
  call.

mysql-test/main/innodb_ext_key.result

@@ -385,9 +385,9 @@ SELECT a FROM t1 AS t, t2
 WHERE c = a AND b IN (SELECT b FROM t1, t2 WHERE b = t.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t	index	a,b	b	7	NULL	10	Using index
+1	PRIMARY	t2	eq_ref	PRIMARY	PRIMARY	4	test.t.a	1	Using index
 1	PRIMARY	t1	ref	b	b	3	test.t.b	2	Using index; Start temporary
 1	PRIMARY	t2	index	NULL	PRIMARY	4	NULL	11	Using index; End temporary; Using join buffer (flat, BNL join)
-1	PRIMARY	t2	eq_ref	PRIMARY	PRIMARY	4	test.t.a	1	Using index
 SELECT a FROM t1 AS t, t2 
 WHERE c = a AND b IN (SELECT b FROM t1, t2 WHERE b = t.b);
 a

mysql-test/main/join_nested.test

@@ -637,6 +637,7 @@ SELECT t0.a,t0.b,t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
            (t8.b=t9.b OR t8.c IS NULL) AND
            (t9.a=1); 
 
+--sorted_result
 SELECT t0.a,t0.b,t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
        t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b,t9.a,t9.b
   FROM t0,t1

mysql-test/main/join_outer.result

@@ -2009,10 +2009,10 @@ EXPLAIN EXTENDED
 SELECT * FROM (t2 LEFT JOIN t1 ON t1.b = t2.b) JOIN t3 ON t1.b = t3.b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
-1	SIMPLE	t3	hash_ALL	PRIMARY	#hash#PRIMARY	4	test.t1.b	10	10.00	Using join buffer (flat, BNLH join)
-1	SIMPLE	t2	hash_index	PRIMARY	#hash#PRIMARY:PRIMARY	4:4	test.t1.b	27	3.70	Using index; Using join buffer (incremental, BNLH join)
+1	SIMPLE	t2	hash_index	PRIMARY	#hash#PRIMARY:PRIMARY	4:4	test.t1.b	27	3.70	Using index; Using join buffer (flat, BNLH join)
+1	SIMPLE	t3	hash_ALL	PRIMARY	#hash#PRIMARY	4	test.t1.b	10	10.00	Using join buffer (incremental, BNLH join)
 Warnings:
-Note	1003	select `test`.`t2`.`b` AS `b`,`test`.`t1`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b` from `test`.`t2` join `test`.`t1` join `test`.`t3` where `test`.`t3`.`b` = `test`.`t1`.`b` and `test`.`t2`.`b` = `test`.`t1`.`b`
+Note	1003	select `test`.`t2`.`b` AS `b`,`test`.`t1`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b` from `test`.`t2` join `test`.`t1` join `test`.`t3` where `test`.`t2`.`b` = `test`.`t1`.`b` and `test`.`t3`.`b` = `test`.`t1`.`b`
 PREPARE stmt FROM
 'SELECT * FROM (t2 LEFT JOIN t1 ON t1.b = t2.b) JOIN t3 ON t1.b = t3.b';
 EXECUTE stmt;
@@ -2644,9 +2644,9 @@ WHERE t1.timestamp < 1294664900039 AND t1.timestamp > 1294644616416  AND
 t2.REVTYPE=2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	42	100.00	Using where
+1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.REV	1	100.00	Using where
 1	SIMPLE	t3	ref	PRIMARY	PRIMARY	4	test.t2.profile_id	1	100.00	Using where
 1	SIMPLE	t4	ref	PRIMARY	PRIMARY	4	test.t3.person_id	1	100.00	Using index
-1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.REV	1	100.00	Using where
 Warnings:
 Note	1003	select `test`.`t1`.`id` AS `id`,`test`.`t1`.`timestamp` AS `timestamp`,`test`.`t1`.`modifiedBy` AS `modifiedBy`,`test`.`t2`.`id` AS `id`,`test`.`t2`.`REV` AS `REV`,`test`.`t2`.`REVTYPE` AS `REVTYPE`,`test`.`t2`.`profile_id` AS `profile_id`,`test`.`t3`.`id` AS `id`,`test`.`t3`.`REV` AS `REV`,`test`.`t3`.`person_id` AS `person_id`,`test`.`t4`.`id` AS `id`,`test`.`t4`.`REV` AS `REV` from `test`.`t1` join `test`.`t2` join `test`.`t3` join `test`.`t4` where `test`.`t2`.`REVTYPE` = 2 and `test`.`t4`.`id` = `test`.`t3`.`person_id` and `test`.`t3`.`id` = `test`.`t2`.`profile_id` and `test`.`t1`.`id` = `test`.`t2`.`REV` and `test`.`t1`.`timestamp` < 1294664900039 and `test`.`t1`.`timestamp` > 1294644616416
 SELECT *
@@ -2669,9 +2669,9 @@ WHERE t1.timestamp < 1294664900039 AND t1.timestamp > 1294644616416
 AND t2.REVTYPE=2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	42	100.00	Using where
+1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.REV	1	100.00	Using where
 1	SIMPLE	t3	ref	PRIMARY	PRIMARY	4	test.t2.profile_id	1	100.00	Using where
 1	SIMPLE	t4	ref	PRIMARY	PRIMARY	4	test.t3.person_id	1	100.00	Using index
-1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.REV	1	100.00	Using where
 Warnings:
 Note	1003	select `test`.`t1`.`id` AS `id`,`test`.`t1`.`timestamp` AS `timestamp`,`test`.`t1`.`modifiedBy` AS `modifiedBy`,`test`.`t2`.`id` AS `id`,`test`.`t2`.`REV` AS `REV`,`test`.`t2`.`REVTYPE` AS `REVTYPE`,`test`.`t2`.`profile_id` AS `profile_id`,`test`.`t3`.`id` AS `id`,`test`.`t3`.`REV` AS `REV`,`test`.`t3`.`person_id` AS `person_id`,`test`.`t4`.`id` AS `id`,`test`.`t4`.`REV` AS `REV` from `test`.`t4` join `test`.`t3` join `test`.`t2` join `test`.`t1` where `test`.`t2`.`REVTYPE` = 2 and `test`.`t1`.`id` = `test`.`t2`.`REV` and `test`.`t3`.`id` = `test`.`t2`.`profile_id` and `test`.`t4`.`id` = `test`.`t3`.`person_id` and `test`.`t1`.`timestamp` < 1294664900039 and `test`.`t1`.`timestamp` > 1294644616416
 SELECT *

mysql-test/main/join_outer_innodb.result

@@ -440,8 +440,8 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t4	eq_ref	PRIMARY	PRIMARY	4	test.t1.a2	1	Using index
 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.d1	1	Using where
 1	SIMPLE	t6	eq_ref	PRIMARY	PRIMARY	4	test.t1.a3	1	Using where; Using index
-1	SIMPLE	t8	eq_ref	PRIMARY	PRIMARY	1	test.t1.a4	1	Using index
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	1	test.t1.a7	1	
+1	SIMPLE	t8	eq_ref	PRIMARY	PRIMARY	1	test.t1.a4	1	Using index
 1	SIMPLE	t9	ref	PRIMARY	PRIMARY	1	test.t1.a4	1	
 1	SIMPLE	t11	eq_ref	PRIMARY	PRIMARY	4	test.t1.a5	1	
 1	SIMPLE	t12	eq_ref	PRIMARY	PRIMARY	4	test.t11.k3	1	Using where
@@ -462,8 +462,8 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t4	eq_ref	PRIMARY	PRIMARY	4	test.t1.a2	1	Using index
 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.d1	1	Using where
 1	SIMPLE	t6	eq_ref	PRIMARY	PRIMARY	4	test.t1.a3	1	Using where; Using index
-1	SIMPLE	t8	eq_ref	PRIMARY	PRIMARY	1	test.t1.a4	1	Using index
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	1	test.t1.a7	1	
+1	SIMPLE	t8	eq_ref	PRIMARY	PRIMARY	1	test.t1.a4	1	Using index
 1	SIMPLE	t9	ref	PRIMARY	PRIMARY	1	test.t1.a4	1	
 1	SIMPLE	t11	eq_ref	PRIMARY	PRIMARY	4	test.t1.a5	1	
 1	SIMPLE	t12	eq_ref	PRIMARY	PRIMARY	4	test.t11.k3	1	Using where

mysql-test/main/join_outer_jcl6.result

@@ -2016,10 +2016,10 @@ EXPLAIN EXTENDED
 SELECT * FROM (t2 LEFT JOIN t1 ON t1.b = t2.b) JOIN t3 ON t1.b = t3.b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
-1	SIMPLE	t3	hash_ALL	PRIMARY	#hash#PRIMARY	4	test.t1.b	10	10.00	Using join buffer (flat, BNLH join)
-1	SIMPLE	t2	hash_index	PRIMARY	#hash#PRIMARY:PRIMARY	4:4	test.t1.b	27	3.70	Using index; Using join buffer (incremental, BNLH join)
+1	SIMPLE	t2	hash_index	PRIMARY	#hash#PRIMARY:PRIMARY	4:4	test.t1.b	27	3.70	Using index; Using join buffer (flat, BNLH join)
+1	SIMPLE	t3	hash_ALL	PRIMARY	#hash#PRIMARY	4	test.t1.b	10	10.00	Using join buffer (incremental, BNLH join)
 Warnings:
-Note	1003	select `test`.`t2`.`b` AS `b`,`test`.`t1`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b` from `test`.`t2` join `test`.`t1` join `test`.`t3` where `test`.`t3`.`b` = `test`.`t1`.`b` and `test`.`t2`.`b` = `test`.`t1`.`b`
+Note	1003	select `test`.`t2`.`b` AS `b`,`test`.`t1`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b` from `test`.`t2` join `test`.`t1` join `test`.`t3` where `test`.`t2`.`b` = `test`.`t1`.`b` and `test`.`t3`.`b` = `test`.`t1`.`b`
 PREPARE stmt FROM
 'SELECT * FROM (t2 LEFT JOIN t1 ON t1.b = t2.b) JOIN t3 ON t1.b = t3.b';
 EXECUTE stmt;
@@ -2651,9 +2651,9 @@ WHERE t1.timestamp < 1294664900039 AND t1.timestamp > 1294644616416  AND
 t2.REVTYPE=2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	42	100.00	Using where
-1	SIMPLE	t3	ref	PRIMARY	PRIMARY	4	test.t2.profile_id	1	100.00	Using where; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
-1	SIMPLE	t4	ref	PRIMARY	PRIMARY	4	test.t3.person_id	1	100.00	Using index
 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.REV	1	100.00	Using where; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
+1	SIMPLE	t3	ref	PRIMARY	PRIMARY	4	test.t2.profile_id	1	100.00	Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
+1	SIMPLE	t4	ref	PRIMARY	PRIMARY	4	test.t3.person_id	1	100.00	Using index
 Warnings:
 Note	1003	select `test`.`t1`.`id` AS `id`,`test`.`t1`.`timestamp` AS `timestamp`,`test`.`t1`.`modifiedBy` AS `modifiedBy`,`test`.`t2`.`id` AS `id`,`test`.`t2`.`REV` AS `REV`,`test`.`t2`.`REVTYPE` AS `REVTYPE`,`test`.`t2`.`profile_id` AS `profile_id`,`test`.`t3`.`id` AS `id`,`test`.`t3`.`REV` AS `REV`,`test`.`t3`.`person_id` AS `person_id`,`test`.`t4`.`id` AS `id`,`test`.`t4`.`REV` AS `REV` from `test`.`t1` join `test`.`t2` join `test`.`t3` join `test`.`t4` where `test`.`t2`.`REVTYPE` = 2 and `test`.`t4`.`id` = `test`.`t3`.`person_id` and `test`.`t3`.`id` = `test`.`t2`.`profile_id` and `test`.`t1`.`id` = `test`.`t2`.`REV` and `test`.`t1`.`timestamp` < 1294664900039 and `test`.`t1`.`timestamp` > 1294644616416
 SELECT *
@@ -2676,9 +2676,9 @@ WHERE t1.timestamp < 1294664900039 AND t1.timestamp > 1294644616416
 AND t2.REVTYPE=2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	42	100.00	Using where
-1	SIMPLE	t3	ref	PRIMARY	PRIMARY	4	test.t2.profile_id	1	100.00	Using where; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
-1	SIMPLE	t4	ref	PRIMARY	PRIMARY	4	test.t3.person_id	1	100.00	Using index
 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.REV	1	100.00	Using where; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
+1	SIMPLE	t3	ref	PRIMARY	PRIMARY	4	test.t2.profile_id	1	100.00	Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
+1	SIMPLE	t4	ref	PRIMARY	PRIMARY	4	test.t3.person_id	1	100.00	Using index
 Warnings:
 Note	1003	select `test`.`t1`.`id` AS `id`,`test`.`t1`.`timestamp` AS `timestamp`,`test`.`t1`.`modifiedBy` AS `modifiedBy`,`test`.`t2`.`id` AS `id`,`test`.`t2`.`REV` AS `REV`,`test`.`t2`.`REVTYPE` AS `REVTYPE`,`test`.`t2`.`profile_id` AS `profile_id`,`test`.`t3`.`id` AS `id`,`test`.`t3`.`REV` AS `REV`,`test`.`t3`.`person_id` AS `person_id`,`test`.`t4`.`id` AS `id`,`test`.`t4`.`REV` AS `REV` from `test`.`t4` join `test`.`t3` join `test`.`t2` join `test`.`t1` where `test`.`t2`.`REVTYPE` = 2 and `test`.`t1`.`id` = `test`.`t2`.`REV` and `test`.`t3`.`id` = `test`.`t2`.`profile_id` and `test`.`t4`.`id` = `test`.`t3`.`person_id` and `test`.`t1`.`timestamp` < 1294664900039 and `test`.`t1`.`timestamp` > 1294644616416
 SELECT *

mysql-test/main/mysqld--help.test

@@ -38,7 +38,8 @@ perl;
               test-sql-discovery query-cache-info password-reuse-check
               query-response-time metadata-lock-info locales unix-socket
               wsrep file-key-management cracklib-password-check user-variables
-              thread-pool-groups thread-pool-queues thread-pool-stats thread-pool-waits/;
+              thread-pool-groups thread-pool-queues thread-pool-stats
+              thread-pool-waits hashicorp provider/;
 
   # And substitute the content some environment variables with their
   # names:

mysql-test/main/opt_trace.test

@@ -885,6 +885,6 @@ set optimizer_trace=0;
 set statement optimizer_trace=1 for select * from seq_1_to_10 where seq<2;
 --echo # The trace must not be empty:
 select left(trace, 100) from information_schema.optimizer_trace;
+set optimizer_trace='enabled=off';
 
 --echo # End of 10.6 tests
-set optimizer_trace='enabled=off';

mysql-test/main/opt_trace_index_merge.result

@@ -219,7 +219,11 @@ explain select * from t1 where a=1 or b=1	{
                     "cost": 2.484903732,
                     "uses_join_buffering": false
                   }
-                },
+                }
+              },
+              {
+                "plan_prefix": [],
+                "table": "t1",
                 "rows_for_plan": 2,
                 "cost_for_plan": 2.884903732
               }

mysql-test/main/opt_trace_index_merge_innodb.result

@@ -225,7 +225,11 @@ explain select * from t1 where pk1 != 0  and key1 = 1	{
                     "cost": 1.125146475,
                     "uses_join_buffering": false
                   }
-                },
+                }
+              },
+              {
+                "plan_prefix": [],
+                "table": "t1",
                 "rows_for_plan": 1,
                 "cost_for_plan": 1.325146475,
                 "pruned_by_hanging_leaf": true

mysql-test/main/opt_trace_security.result

@@ -105,7 +105,11 @@ select * from db1.t1	{
                     "cost": 2.005126953,
                     "uses_join_buffering": false
                   }
-                },
+                }
+              },
+              {
+                "plan_prefix": [],
+                "table": "t1",
                 "rows_for_plan": 3,
                 "cost_for_plan": 2.605126953
               }
@@ -226,7 +230,11 @@ select * from db1.v1	{
                     "cost": 2.005126953,
                     "uses_join_buffering": false
                   }
-                },
+                }
+              },
+              {
+                "plan_prefix": [],
+                "table": "t1",
                 "rows_for_plan": 3,
                 "cost_for_plan": 2.605126953
               }

mysql-test/main/opt_tvc.result

@@ -91,10 +91,10 @@ where a in (1,2) and
 b in (1,5);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	6	100.00	
-1	PRIMARY	<subquery4>	eq_ref	distinct_key	distinct_key	4	func	1	100.00	
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	100.00	
-4	MATERIALIZED	<derived5>	ALL	NULL	NULL	NULL	NULL	2	100.00	
+1	PRIMARY	<subquery4>	eq_ref	distinct_key	distinct_key	4	func	1	100.00	
 2	MATERIALIZED	<derived3>	ALL	NULL	NULL	NULL	NULL	2	100.00	
+4	MATERIALIZED	<derived5>	ALL	NULL	NULL	NULL	NULL	2	100.00	
 5	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 3	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 Warnings:
@@ -112,10 +112,10 @@ from (values (1),(5)) as tvc_1
 );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	6	100.00	
-1	PRIMARY	<subquery4>	eq_ref	distinct_key	distinct_key	4	func	1	100.00	
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	100.00	
-4	MATERIALIZED	<derived5>	ALL	NULL	NULL	NULL	NULL	2	100.00	
+1	PRIMARY	<subquery4>	eq_ref	distinct_key	distinct_key	4	func	1	100.00	
 2	MATERIALIZED	<derived3>	ALL	NULL	NULL	NULL	NULL	2	100.00	
+4	MATERIALIZED	<derived5>	ALL	NULL	NULL	NULL	NULL	2	100.00	
 5	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 3	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 Warnings:

mysql-test/main/selectivity.result

@@ -486,8 +486,8 @@ order by s_name
 limit 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	supplier	ALL	PRIMARY,i_s_nationkey	NULL	NULL	NULL	10	100.00	Using where; Using filesort
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	100.00	
 1	PRIMARY	nation	eq_ref	PRIMARY	PRIMARY	4	dbt3_s001.supplier.s_nationkey	1	100.00	Using where
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	100.00	
 2	MATERIALIZED	part	ALL	PRIMARY	NULL	NULL	NULL	200	100.00	Using where
 2	MATERIALIZED	partsupp	ref	PRIMARY,i_ps_partkey,i_ps_suppkey	i_ps_partkey	4	dbt3_s001.part.p_partkey	3	100.00	Using where
 4	DEPENDENT SUBQUERY	lineitem	ref	i_l_shipdate,i_l_suppkey_partkey,i_l_partkey,i_l_suppkey	i_l_suppkey_partkey	10	dbt3_s001.partsupp.ps_partkey,dbt3_s001.partsupp.ps_suppkey	8	100.00	Using where
@@ -1245,11 +1245,11 @@ EXPLAIN EXTENDED
 SELECT * FROM language, country, continent
 WHERE country_group = lang_group AND lang_group IS NULL;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	country	ALL	NULL	NULL	NULL	NULL	2	50.00	Using where
-1	SIMPLE	language	ALL	NULL	NULL	NULL	NULL	6	16.67	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	language	ALL	NULL	NULL	NULL	NULL	6	16.67	Using where
+1	SIMPLE	country	ALL	NULL	NULL	NULL	NULL	2	50.00	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	continent	ALL	NULL	NULL	NULL	NULL	6	100.00	Using join buffer (incremental, BNL join)
 Warnings:
-Note	1003	select `test`.`language`.`lang_group` AS `lang_group`,`test`.`language`.`lang` AS `lang`,`test`.`country`.`code` AS `code`,`test`.`country`.`country_group` AS `country_group`,`test`.`continent`.`cont_group` AS `cont_group`,`test`.`continent`.`cont` AS `cont` from `test`.`language` join `test`.`country` join `test`.`continent` where `test`.`language`.`lang_group` = `test`.`country`.`country_group` and `test`.`country`.`country_group` is null
+Note	1003	select `test`.`language`.`lang_group` AS `lang_group`,`test`.`language`.`lang` AS `lang`,`test`.`country`.`code` AS `code`,`test`.`country`.`country_group` AS `country_group`,`test`.`continent`.`cont_group` AS `cont_group`,`test`.`continent`.`cont` AS `cont` from `test`.`language` join `test`.`country` join `test`.`continent` where `test`.`country`.`country_group` = `test`.`language`.`lang_group` and `test`.`language`.`lang_group` is null
 set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
 drop table language, country, continent;
 set use_stat_tables=@save_use_stat_tables;
@@ -1769,8 +1769,8 @@ explain extended select t1.b,t2.a,t3.a,t3.b from t1,t2,t3
 where t1.c = t2.a AND t1.d = t3.a and t1.a = 50 and t1.b <= 100;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	range	a	a	10	NULL	9	100.00	Using index condition; Using where
-1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.d	1	100.00	
 1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.c	1	100.00	Using index
+1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.d	1	100.00	
 Warnings:
 Note	1003	select `test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b` from `test`.`t1` join `test`.`t2` join `test`.`t3` where `test`.`t2`.`a` = `test`.`t1`.`c` and `test`.`t3`.`a` = `test`.`t1`.`d` and `test`.`t1`.`a` = 50 and `test`.`t1`.`b` <= 100
 select t1.b,t2.a,t3.a,t3.b from t1,t2,t3
@@ -1791,8 +1791,8 @@ explain extended select t1.b,t2.a,t3.a,t3.b from t1,t2,t3
 where t1.c = t2.a AND t1.d = t3.a and t1.a = 50 and t1.b <= 100;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	range	a	a	10	NULL	9	9.00	Using index condition; Using where
-1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.d	1	100.00	
 1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.c	1	100.00	Using index
+1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.d	1	100.00	
 Warnings:
 Note	1003	select `test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b` from `test`.`t1` join `test`.`t2` join `test`.`t3` where `test`.`t2`.`a` = `test`.`t1`.`c` and `test`.`t3`.`a` = `test`.`t1`.`d` and `test`.`t1`.`a` = 50 and `test`.`t1`.`b` <= 100
 select t1.b,t2.a,t3.a,t3.b from t1,t2,t3

mysql-test/main/selectivity_innodb.result

@@ -491,8 +491,8 @@ order by s_name
 limit 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	supplier	ALL	PRIMARY,i_s_nationkey	NULL	NULL	NULL	10	100.00	Using where; Using filesort
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	100.00	
 1	PRIMARY	nation	eq_ref	PRIMARY	PRIMARY	4	dbt3_s001.supplier.s_nationkey	1	100.00	Using where
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	100.00	
 2	MATERIALIZED	part	ALL	PRIMARY	NULL	NULL	NULL	200	100.00	Using where
 2	MATERIALIZED	partsupp	ref	PRIMARY,i_ps_partkey,i_ps_suppkey	PRIMARY	4	dbt3_s001.part.p_partkey	3	100.00	Using where
 4	DEPENDENT SUBQUERY	lineitem	ref	i_l_shipdate,i_l_suppkey_partkey,i_l_partkey,i_l_suppkey	i_l_suppkey_partkey	10	dbt3_s001.partsupp.ps_partkey,dbt3_s001.partsupp.ps_suppkey	8	100.00	Using where
@@ -1257,11 +1257,11 @@ EXPLAIN EXTENDED
 SELECT * FROM language, country, continent
 WHERE country_group = lang_group AND lang_group IS NULL;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	country	ALL	NULL	NULL	NULL	NULL	2	50.00	Using where
-1	SIMPLE	language	ALL	NULL	NULL	NULL	NULL	6	16.67	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	language	ALL	NULL	NULL	NULL	NULL	6	0.00	Using where
+1	SIMPLE	country	ALL	NULL	NULL	NULL	NULL	2	0.00	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	continent	ALL	NULL	NULL	NULL	NULL	6	100.00	Using join buffer (incremental, BNL join)
 Warnings:
-Note	1003	select `test`.`language`.`lang_group` AS `lang_group`,`test`.`language`.`lang` AS `lang`,`test`.`country`.`code` AS `code`,`test`.`country`.`country_group` AS `country_group`,`test`.`continent`.`cont_group` AS `cont_group`,`test`.`continent`.`cont` AS `cont` from `test`.`language` join `test`.`country` join `test`.`continent` where `test`.`language`.`lang_group` = `test`.`country`.`country_group` and `test`.`country`.`country_group` is null
+Note	1003	select `test`.`language`.`lang_group` AS `lang_group`,`test`.`language`.`lang` AS `lang`,`test`.`country`.`code` AS `code`,`test`.`country`.`country_group` AS `country_group`,`test`.`continent`.`cont_group` AS `cont_group`,`test`.`continent`.`cont` AS `cont` from `test`.`language` join `test`.`country` join `test`.`continent` where `test`.`country`.`country_group` = `test`.`language`.`lang_group` and `test`.`language`.`lang_group` is null
 set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
 drop table language, country, continent;
 set use_stat_tables=@save_use_stat_tables;
@@ -1781,8 +1781,8 @@ explain extended select t1.b,t2.a,t3.a,t3.b from t1,t2,t3
 where t1.c = t2.a AND t1.d = t3.a and t1.a = 50 and t1.b <= 100;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	range	a	a	10	NULL	11	100.00	Using index condition; Using where
-1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.d	1	100.00	
 1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.c	1	100.00	Using index
+1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.d	1	100.00	
 Warnings:
 Note	1003	select `test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b` from `test`.`t1` join `test`.`t2` join `test`.`t3` where `test`.`t2`.`a` = `test`.`t1`.`c` and `test`.`t3`.`a` = `test`.`t1`.`d` and `test`.`t1`.`a` = 50 and `test`.`t1`.`b` <= 100
 select t1.b,t2.a,t3.a,t3.b from t1,t2,t3
@@ -1803,8 +1803,8 @@ explain extended select t1.b,t2.a,t3.a,t3.b from t1,t2,t3
 where t1.c = t2.a AND t1.d = t3.a and t1.a = 50 and t1.b <= 100;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	range	a	a	10	NULL	11	11.00	Using index condition; Using where
-1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.d	1	100.00	
 1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.c	1	100.00	Using index
+1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.d	1	100.00	
 Warnings:
 Note	1003	select `test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b` from `test`.`t1` join `test`.`t2` join `test`.`t3` where `test`.`t2`.`a` = `test`.`t1`.`c` and `test`.`t3`.`a` = `test`.`t1`.`d` and `test`.`t1`.`a` = 50 and `test`.`t1`.`b` <= 100
 select t1.b,t2.a,t3.a,t3.b from t1,t2,t3

mysql-test/main/stat_tables.result

@@ -217,9 +217,9 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	lineitem	ref	PRIMARY,i_l_suppkey_partkey,i_l_partkey,i_l_suppkey,i_l_orderkey,i_l_orderkey_quantity	i_l_partkey	5	dbt3_s001.part.p_partkey	30	Using where
 1	SIMPLE	supplier	eq_ref	PRIMARY,i_s_nationkey	PRIMARY	4	dbt3_s001.lineitem.l_suppkey	1	Using where
 1	SIMPLE	orders	eq_ref|filter	PRIMARY,i_o_orderdate,i_o_custkey	PRIMARY|i_o_orderdate	4|4	dbt3_s001.lineitem.l_orderkey	1 (27%)	Using where; Using rowid filter
-1	SIMPLE	n2	eq_ref	PRIMARY	PRIMARY	4	dbt3_s001.supplier.s_nationkey	1	
 1	SIMPLE	customer	eq_ref	PRIMARY,i_c_nationkey	PRIMARY	4	dbt3_s001.orders.o_custkey	1	Using where
 1	SIMPLE	n1	eq_ref	PRIMARY,i_n_regionkey	PRIMARY	4	dbt3_s001.customer.c_nationkey	1	Using where
+1	SIMPLE	n2	eq_ref	PRIMARY	PRIMARY	4	dbt3_s001.supplier.s_nationkey	1	
 select o_year,
 sum(case when nation = 'UNITED STATES' then volume else 0 end) /
 sum(volume) as mkt_share

mysql-test/main/stat_tables_innodb.result

@@ -248,10 +248,10 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	part	ALL	PRIMARY	NULL	NULL	NULL	200	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	lineitem	ref	PRIMARY,i_l_suppkey_partkey,i_l_partkey,i_l_suppkey,i_l_orderkey,i_l_orderkey_quantity	i_l_partkey	5	dbt3_s001.part.p_partkey	30	Using where
 1	SIMPLE	supplier	eq_ref	PRIMARY,i_s_nationkey	PRIMARY	4	dbt3_s001.lineitem.l_suppkey	1	Using where
-1	SIMPLE	n2	eq_ref	PRIMARY	PRIMARY	4	dbt3_s001.supplier.s_nationkey	1	
 1	SIMPLE	orders	eq_ref	PRIMARY,i_o_orderdate,i_o_custkey	PRIMARY	4	dbt3_s001.lineitem.l_orderkey	1	Using where
 1	SIMPLE	customer	eq_ref	PRIMARY,i_c_nationkey	PRIMARY	4	dbt3_s001.orders.o_custkey	1	Using where
 1	SIMPLE	n1	eq_ref	PRIMARY,i_n_regionkey	PRIMARY	4	dbt3_s001.customer.c_nationkey	1	Using where
+1	SIMPLE	n2	eq_ref	PRIMARY	PRIMARY	4	dbt3_s001.supplier.s_nationkey	1	
 select o_year,
 sum(case when nation = 'UNITED STATES' then volume else 0 end) /
 sum(volume) as mkt_share

mysql-test/main/subselect2.result

@@ -126,8 +126,8 @@ c373e9f5ad07993f3859444553544200	Last Discussion	c373e9f5ad079174ff1744455354420
 EXPLAIN SELECT t2.*, t4.DOCTYPENAME, t1.CONTENTSIZE,t1.MIMETYPE FROM t2 INNER JOIN t4 ON t2.DOCTYPEID = t4.DOCTYPEID LEFT OUTER JOIN t1 ON t2.DOCID = t1.DOCID WHERE t2.FOLDERID IN(SELECT t3.FOLDERID FROM t3 WHERE t3.PARENTID IN(SELECT t3.FOLDERID FROM t3 WHERE t3.PARENTID IN(SELECT t3.FOLDERID FROM t3 WHERE t3.PARENTID IN(SELECT t3.FOLDERID FROM t3 WHERE t3.PARENTID IN(SELECT t3.FOLDERID FROM t3 WHERE t3.PARENTID='2f6161e879db43c1a5b82c21ddc49089' AND t3.FOLDERNAME = 'Level1') AND t3.FOLDERNAME = 'Level2') AND t3.FOLDERNAME = 'Level3') AND t3.FOLDERNAME = 'CopiedFolder') AND t3.FOLDERNAME = 'Movie Reviews') AND t2.DOCNAME = 'Last Discussion';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	DDOCTYPEID_IDX,DFOLDERID_IDX	NULL	NULL	NULL	9	Using where
-1	PRIMARY	t1	eq_ref	PRIMARY	PRIMARY	34	test.t2.DOCID	1	
 1	PRIMARY	t4	eq_ref	PRIMARY	PRIMARY	34	test.t2.DOCTYPEID	1	
+1	PRIMARY	t1	eq_ref	PRIMARY	PRIMARY	34	test.t2.DOCID	1	
 1	PRIMARY	t3	eq_ref	PRIMARY,FFOLDERID_IDX,CMFLDRPARNT_IDX	PRIMARY	34	test.t2.FOLDERID	1	Using where
 1	PRIMARY	t3	eq_ref	PRIMARY,FFOLDERID_IDX,CMFLDRPARNT_IDX	PRIMARY	34	test.t3.PARENTID	1	Using where
 1	PRIMARY	t3	eq_ref	PRIMARY,FFOLDERID_IDX,CMFLDRPARNT_IDX	PRIMARY	34	test.t3.PARENTID	1	Using where

mysql-test/main/subselect_sj.result

@@ -1056,10 +1056,10 @@ AND t1.val IN (SELECT t3.val FROM t3
 WHERE  t3.val LIKE 'a%' OR t3.val LIKE 'e%');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	
-1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	13	func	1	
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	13	func	1	
-3	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	5	Using where
+1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	13	func	1	
 2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
+3	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	5	Using where
 SELECT *
 FROM t1
 WHERE t1.val IN (SELECT t2.val FROM t2
@@ -1610,9 +1610,9 @@ A.t1field IN (SELECT C.t2field FROM t2 C
 WHERE C.t2field IN (SELECT D.t2field FROM t2 D));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	A	index	PRIMARY	PRIMARY	4	NULL	3	Using index
-1	PRIMARY	B	index	NULL	PRIMARY	4	NULL	3	Using index; Start temporary; End temporary
 1	PRIMARY	C	eq_ref	PRIMARY	PRIMARY	4	test.A.t1field	1	Using index
 1	PRIMARY	D	eq_ref	PRIMARY	PRIMARY	4	test.A.t1field	1	Using index
+1	PRIMARY	B	index	NULL	PRIMARY	4	NULL	3	Using index; Start temporary; End temporary
 SELECT * FROM t1 A 
 WHERE 
 A.t1field IN (SELECT A.t1field FROM t2 B) AND 
@@ -2179,8 +2179,8 @@ explain
 SELECT * FROM t3 WHERE t3.a IN (SELECT t5.a FROM t2, t4, t5 WHERE t2.c = t5.a AND t2.b = t5.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t5	index	a	a	10	NULL	2	Using where; Using index; LooseScan
-1	PRIMARY	t4	ALL	NULL	NULL	NULL	NULL	3	
-1	PRIMARY	t2	ref	b	b	5	test.t5.b	2	Using where; FirstMatch(t5)
+1	PRIMARY	t2	ref	b	b	5	test.t5.b	2	Using where
+1	PRIMARY	t4	ALL	NULL	NULL	NULL	NULL	3	FirstMatch(t5)
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	15	Using where; Using join buffer (flat, BNL join)
 SELECT * FROM t3 WHERE t3.a IN (SELECT t5.a FROM t2, t4, t5 WHERE t2.c = t5.a AND t2.b = t5.b);
 a
@@ -2260,11 +2260,11 @@ alias1.c IN (SELECT SQ3_alias1.b
 FROM t2 AS SQ3_alias1 STRAIGHT_JOIN t2 AS SQ3_alias2)
 LIMIT 100;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	SQ3_alias1	ALL	NULL	NULL	NULL	NULL	20	Start temporary
-1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	20	Using where; Using join buffer (flat, BNL join)
-1	PRIMARY	SQ3_alias2	index	NULL	PRIMARY	4	NULL	20	Using index; End temporary
+1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	20	
 1	PRIMARY	alias2	ALL	NULL	NULL	NULL	NULL	20	Using join buffer (flat, BNL join)
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	20	Using join buffer (flat, BNL join)
+1	PRIMARY	SQ3_alias1	ALL	NULL	NULL	NULL	NULL	20	Using where; Start temporary
+1	PRIMARY	SQ3_alias2	index	NULL	PRIMARY	4	NULL	20	Using index; End temporary
 2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	20	
 create table t3 as
 SELECT 

mysql-test/main/subselect_sj2.result

@@ -466,11 +466,20 @@ where t0.a in ( select t1.a from t1,t2 where t2.a=t0.a and
 t1.b=t2.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where
-1	PRIMARY	t1	ref	a	a	5	test.t0.a	1	100.00	Start temporary
-1	PRIMARY	t2	eq_ref	PRIMARY	PRIMARY	4	test.t0.a	1	100.00	Using where; End temporary
+1	PRIMARY	t2	eq_ref	PRIMARY	PRIMARY	4	test.t0.a	1	100.00	
+1	PRIMARY	t1	ref	a	a	5	test.t0.a	1	100.00	Using where; FirstMatch(t2)
 Warnings:
 Note	1276	Field or reference 'test.t0.a' of SELECT #2 was resolved in SELECT #1
-Note	1003	select `test`.`t0`.`a` AS `a` from `test`.`t2` semi join (`test`.`t1`) join `test`.`t0` where `test`.`t1`.`a` = `test`.`t0`.`a` and `test`.`t2`.`a` = `test`.`t0`.`a` and `test`.`t2`.`b` = `test`.`t1`.`b`
+Note	1003	select `test`.`t0`.`a` AS `a` from `test`.`t2` semi join (`test`.`t1`) join `test`.`t0` where `test`.`t2`.`a` = `test`.`t0`.`a` and `test`.`t1`.`a` = `test`.`t0`.`a` and `test`.`t1`.`b` = `test`.`t2`.`b`
+select * from t0
+where t0.a in ( select t1.a from t1,t2 where t2.a=t0.a and
+t1.b=t2.b);
+a
+0
+1
+2
+3
+4
 update t1 set a=3, b=11 where a=4;
 update t2 set b=11 where a=3;
 select * from t0 where t0.a in 
@@ -759,10 +768,14 @@ c2 in (select 1 from t3, t2) and
 c1 in (select convert(c6,char(1)) from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where
-1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	2	FirstMatch((sj-nest))
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	2	FirstMatch(t2)
+1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
 3	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	1	
+select 1 from t2 where 
+c2 in (select 1 from t3, t2) and
+c1 in (select convert(c6,char(1)) from t2);
+1
 drop table t2, t3;
 #
 # BUG#761598: InnoDB: Error: row_search_for_mysql() is called without ha_innobase::external_lock() in maria-5.3

mysql-test/main/subselect_sj2.test

@@ -604,6 +604,9 @@ insert into t2 select * from t1;
 explain extended select * from t0
 where t0.a in ( select t1.a from t1,t2 where t2.a=t0.a and
 t1.b=t2.b);
+select * from t0
+where t0.a in ( select t1.a from t1,t2 where t2.a=t0.a and
+t1.b=t2.b);
 
 #
 # BUG#46556 "Returning incorrect, empty results for some IN subqueries 
@@ -934,6 +937,9 @@ create table t2 (c1 tinytext,c2 text,c6 timestamp) engine=innodb;
 explain select 1 from t2 where 
   c2 in (select 1 from t3, t2) and
   c1 in (select convert(c6,char(1)) from t2);
+select 1 from t2 where 
+  c2 in (select 1 from t3, t2) and
+  c1 in (select convert(c6,char(1)) from t2);
 drop table t2, t3;
 
 

mysql-test/main/subselect_sj2_jcl6.result

@@ -477,11 +477,20 @@ where t0.a in ( select t1.a from t1,t2 where t2.a=t0.a and
 t1.b=t2.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where
-1	PRIMARY	t1	ref	a	a	5	test.t0.a	1	100.00	Start temporary; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
-1	PRIMARY	t2	eq_ref	PRIMARY	PRIMARY	4	test.t0.a	1	100.00	Using where; End temporary; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
+1	PRIMARY	t2	eq_ref	PRIMARY	PRIMARY	4	test.t0.a	1	100.00	Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
+1	PRIMARY	t1	ref	a	a	5	test.t0.a	1	100.00	Using where; FirstMatch(t2); Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
 Warnings:
 Note	1276	Field or reference 'test.t0.a' of SELECT #2 was resolved in SELECT #1
-Note	1003	select `test`.`t0`.`a` AS `a` from `test`.`t2` semi join (`test`.`t1`) join `test`.`t0` where `test`.`t1`.`a` = `test`.`t0`.`a` and `test`.`t2`.`a` = `test`.`t0`.`a` and `test`.`t2`.`b` = `test`.`t1`.`b`
+Note	1003	select `test`.`t0`.`a` AS `a` from `test`.`t2` semi join (`test`.`t1`) join `test`.`t0` where `test`.`t2`.`a` = `test`.`t0`.`a` and `test`.`t1`.`a` = `test`.`t0`.`a` and `test`.`t1`.`b` = `test`.`t2`.`b`
+select * from t0
+where t0.a in ( select t1.a from t1,t2 where t2.a=t0.a and
+t1.b=t2.b);
+a
+0
+1
+2
+3
+4
 update t1 set a=3, b=11 where a=4;
 update t2 set b=11 where a=3;
 # Not anymore:
@@ -772,10 +781,14 @@ c2 in (select 1 from t3, t2) and
 c1 in (select convert(c6,char(1)) from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where
-1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using join buffer (flat, BNL join)
-1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	2	FirstMatch((sj-nest)); Using join buffer (incremental, BNL join)
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	2	FirstMatch(t2); Using join buffer (incremental, BNL join)
+1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
 3	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	1	
+select 1 from t2 where 
+c2 in (select 1 from t3, t2) and
+c1 in (select convert(c6,char(1)) from t2);
+1
 drop table t2, t3;
 #
 # BUG#761598: InnoDB: Error: row_search_for_mysql() is called without ha_innobase::external_lock() in maria-5.3

mysql-test/main/subselect_sj2_mat.result

@@ -468,11 +468,20 @@ where t0.a in ( select t1.a from t1,t2 where t2.a=t0.a and
 t1.b=t2.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where
-1	PRIMARY	t1	ref	a	a	5	test.t0.a	1	100.00	Start temporary
-1	PRIMARY	t2	eq_ref	PRIMARY	PRIMARY	4	test.t0.a	1	100.00	Using where; End temporary
+1	PRIMARY	t2	eq_ref	PRIMARY	PRIMARY	4	test.t0.a	1	100.00	
+1	PRIMARY	t1	ref	a	a	5	test.t0.a	1	100.00	Using where; FirstMatch(t2)
 Warnings:
 Note	1276	Field or reference 'test.t0.a' of SELECT #2 was resolved in SELECT #1
-Note	1003	select `test`.`t0`.`a` AS `a` from `test`.`t2` semi join (`test`.`t1`) join `test`.`t0` where `test`.`t1`.`a` = `test`.`t0`.`a` and `test`.`t2`.`a` = `test`.`t0`.`a` and `test`.`t2`.`b` = `test`.`t1`.`b`
+Note	1003	select `test`.`t0`.`a` AS `a` from `test`.`t2` semi join (`test`.`t1`) join `test`.`t0` where `test`.`t2`.`a` = `test`.`t0`.`a` and `test`.`t1`.`a` = `test`.`t0`.`a` and `test`.`t1`.`b` = `test`.`t2`.`b`
+select * from t0
+where t0.a in ( select t1.a from t1,t2 where t2.a=t0.a and
+t1.b=t2.b);
+a
+0
+1
+2
+3
+4
 update t1 set a=3, b=11 where a=4;
 update t2 set b=11 where a=3;
 select * from t0 where t0.a in 
@@ -761,10 +770,14 @@ c2 in (select 1 from t3, t2) and
 c1 in (select convert(c6,char(1)) from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where
-1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	2	FirstMatch((sj-nest))
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	2	FirstMatch(t2)
+1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
 3	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	1	
+select 1 from t2 where 
+c2 in (select 1 from t3, t2) and
+c1 in (select convert(c6,char(1)) from t2);
+1
 drop table t2, t3;
 #
 # BUG#761598: InnoDB: Error: row_search_for_mysql() is called without ha_innobase::external_lock() in maria-5.3
@@ -1481,8 +1494,8 @@ t3.cat_id IN (SELECT cat_id FROM t2) AND
 t3.sack_id = 33479 AND t3.kit_id = 6;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	ref	PRIMARY	PRIMARY	5	const,const	5	Using index
-1	PRIMARY	t2	ref	cat_id	cat_id	4	test.t3.cat_id	2	Using where; Using index; FirstMatch(t3)
-1	PRIMARY	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.cat_id	1	Using where; Using index
+1	PRIMARY	t1	eq_ref	PRIMARY	PRIMARY	4	test.t3.cat_id	1	Using index
+1	PRIMARY	t2	ref	cat_id	cat_id	4	test.t3.cat_id	2	Using where; Using index; FirstMatch(t1)
 SELECT count(*) FROM t1, t3 
 WHERE  t1.cat_id = t3.cat_id AND 
 t3.cat_id IN (SELECT cat_id FROM t2) AND 
@@ -1497,8 +1510,8 @@ t3.cat_id IN (SELECT cat_id FROM t4) AND
 t3.sack_id = 33479 AND t3.kit_id = 6;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	ref	PRIMARY	PRIMARY	5	const,const	5	Using index
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 1	PRIMARY	t1	eq_ref	PRIMARY	PRIMARY	4	test.t3.cat_id	1	Using index
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	t4	index	cat_id	cat_id	4	NULL	19	Using index
 SELECT count(*) FROM t1, t3 
 WHERE  t1.cat_id = t3.cat_id AND 
@@ -1513,8 +1526,8 @@ t3.cat_id IN (SELECT cat_id FROM t2) AND
 t3.sack_id = 33479 AND t3.kit_id = 6;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	ref	PRIMARY	PRIMARY	5	const,const	5	Using index
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
 1	PRIMARY	t1	eq_ref	PRIMARY	PRIMARY	4	test.t3.cat_id	1	Using index
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
 2	MATERIALIZED	t2	index	cat_id	cat_id	4	NULL	19	Using index
 SELECT count(*) FROM t1, t3 
 WHERE  t1.cat_id = t3.cat_id AND 
@@ -1542,9 +1555,9 @@ EXPLAIN EXTENDED
 SELECT * FROM t1 LEFT JOIN t2 ON ( b1 = a2 ) 
 WHERE ( b1, b1 )  IN ( SELECT a4, b4 FROM t3, t4);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Start temporary
-1	PRIMARY	t4	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (flat, BNL join)
-1	PRIMARY	t1	ref	idx	idx	2	test.t4.a4	1	100.00	Using index; End temporary
+1	PRIMARY	t4	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Start temporary
+1	PRIMARY	t1	ref	idx	idx	2	test.t4.a4	1	100.00	Using index
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	End temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`b1` AS `b1`,`test`.`t2`.`a2` AS `a2`,`test`.`t2`.`b2` AS `b2` from `test`.`t1` semi join (`test`.`t3` join `test`.`t4`) left join `test`.`t2` on(`test`.`t2`.`a2` = `test`.`t4`.`a4`) where `test`.`t4`.`b4` = `test`.`t4`.`a4` and `test`.`t1`.`b1` = `test`.`t4`.`a4`
@@ -1560,13 +1573,12 @@ EXPLAIN EXTENDED
 SELECT * FROM t1 LEFT JOIN t2 ON ( b1 = a2 ) 
 WHERE ( b1, b1 )  IN ( SELECT a4, b4 FROM t3, t4);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	3	100.00	
+1	PRIMARY	t4	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Start temporary
 1	PRIMARY	t1	ref	idx	idx	2	test.t4.a4	1	100.00	Using index
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	End temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (flat, BNL join)
-2	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	
-2	MATERIALIZED	t4	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (flat, BNL join)
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`b1` AS `b1`,`test`.`t2`.`a2` AS `a2`,`test`.`t2`.`b2` AS `b2` from `test`.`t1` semi join (`test`.`t3` join `test`.`t4`) left join `test`.`t2` on(`test`.`t1`.`b1` = `test`.`t4`.`a4` and `test`.`t2`.`a2` = `test`.`t4`.`a4`) where `test`.`t4`.`b4` = `test`.`t4`.`a4` and `test`.`t1`.`b1` = `test`.`t4`.`a4`
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`b1` AS `b1`,`test`.`t2`.`a2` AS `a2`,`test`.`t2`.`b2` AS `b2` from `test`.`t1` semi join (`test`.`t3` join `test`.`t4`) left join `test`.`t2` on(`test`.`t2`.`a2` = `test`.`t4`.`a4`) where `test`.`t4`.`b4` = `test`.`t4`.`a4` and `test`.`t1`.`b1` = `test`.`t4`.`a4`
 SELECT * FROM t1 LEFT JOIN t2 ON ( b1 = a2 ) 
 WHERE ( b1, b1 )  IN ( SELECT a4, b4 FROM t3, t4);
 a1	b1	a2	b2
@@ -1827,8 +1839,8 @@ SELECT t2.id FROM t2,t1
 WHERE  t2.id IN (SELECT t3.ref_id FROM t3,t1 where t3.id = t1.id) and t2.id = t1.id;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	index	PRIMARY	PRIMARY	4	NULL	30	Using index
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
 1	PRIMARY	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.id	1	Using index
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
 2	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	14	
 2	MATERIALIZED	t1	eq_ref	PRIMARY	PRIMARY	4	test.t3.id	1	Using index
 SELECT t2.id FROM t2,t1
@@ -1933,19 +1945,19 @@ AND t3.id_product IN (SELECT id_product FROM t2 t2_4 WHERE t2_4.id_t2 = 34 OR t2
 AND t3.id_product IN (SELECT id_product FROM t2 t2_5 WHERE t2_5.id_t2 = 29 OR t2_5.id_t2 = 28 OR t2_5.id_t2 = 26);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	index	PRIMARY	PRIMARY	4	NULL	18	Using index
-1	PRIMARY	<subquery5>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
+1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
 1	PRIMARY	t5	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
-1	PRIMARY	<subquery6>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
 1	PRIMARY	t4	eq_ref	PRIMARY	PRIMARY	8	test.t3.id_product,const	1	Using where; Using index
-1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
-1	PRIMARY	t1	index	NULL	PRIMARY	8	NULL	73	Using where; Using index; Using join buffer (flat, BNL join)
-1	PRIMARY	<subquery4>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
-5	MATERIALIZED	t2_4	range	id_t2,id_product	id_t2	5	NULL	18	Using index condition; Using where
-6	MATERIALIZED	t2_5	range	id_t2,id_product	id_t2	5	NULL	31	Using index condition; Using where
+1	PRIMARY	<subquery4>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
+1	PRIMARY	<subquery5>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
+1	PRIMARY	t1	index	NULL	PRIMARY	8	NULL	73	Using where; Using index; Using join buffer (flat, BNL join)
+1	PRIMARY	<subquery6>	eq_ref	distinct_key	distinct_key	4	func	1	Using where
 3	MATERIALIZED	t2_2	ref	id_t2,id_product	id_t2	5	const	12	
-4	MATERIALIZED	t2_3	range	id_t2,id_product	id_t2	5	NULL	33	Using index condition; Using where
 2	MATERIALIZED	t2_1	ALL	id_t2,id_product	NULL	NULL	NULL	223	Using where
+4	MATERIALIZED	t2_3	range	id_t2,id_product	id_t2	5	NULL	33	Using index condition; Using where
+5	MATERIALIZED	t2_4	range	id_t2,id_product	id_t2	5	NULL	18	Using index condition; Using where
+6	MATERIALIZED	t2_5	range	id_t2,id_product	id_t2	5	NULL	31	Using index condition; Using where
 set optimizer_switch='rowid_filter=default';
 drop table t1,t2,t3,t4,t5;
 set global innodb_stats_persistent= @innodb_stats_persistent_save;

mysql-test/main/subselect_sj_jcl6.result

@@ -1067,10 +1067,10 @@ AND t1.val IN (SELECT t3.val FROM t3
 WHERE  t3.val LIKE 'a%' OR t3.val LIKE 'e%');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	
-1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	13	func	1	
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	13	func	1	
-3	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	5	Using where
+1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	13	func	1	
 2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
+3	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	5	Using where
 SELECT *
 FROM t1
 WHERE t1.val IN (SELECT t2.val FROM t2
@@ -1621,9 +1621,9 @@ A.t1field IN (SELECT C.t2field FROM t2 C
 WHERE C.t2field IN (SELECT D.t2field FROM t2 D));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	A	index	PRIMARY	PRIMARY	4	NULL	3	Using index
-1	PRIMARY	B	index	NULL	PRIMARY	4	NULL	3	Using index; FirstMatch(A); Using join buffer (flat, BNL join)
 1	PRIMARY	C	eq_ref	PRIMARY	PRIMARY	4	test.A.t1field	1	Using index
 1	PRIMARY	D	eq_ref	PRIMARY	PRIMARY	4	test.A.t1field	1	Using index
+1	PRIMARY	B	index	NULL	PRIMARY	4	NULL	3	Using index; FirstMatch(D); Using join buffer (flat, BNL join)
 SELECT * FROM t1 A 
 WHERE 
 A.t1field IN (SELECT A.t1field FROM t2 B) AND 
@@ -2190,8 +2190,8 @@ explain
 SELECT * FROM t3 WHERE t3.a IN (SELECT t5.a FROM t2, t4, t5 WHERE t2.c = t5.a AND t2.b = t5.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t5	index	a	a	10	NULL	2	Using where; Using index; LooseScan
-1	PRIMARY	t4	ALL	NULL	NULL	NULL	NULL	3	
-1	PRIMARY	t2	ref	b	b	5	test.t5.b	2	Using where; FirstMatch(t5)
+1	PRIMARY	t2	ref	b	b	5	test.t5.b	2	Using where
+1	PRIMARY	t4	ALL	NULL	NULL	NULL	NULL	3	FirstMatch(t5)
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	15	Using where; Using join buffer (flat, BNL join)
 SELECT * FROM t3 WHERE t3.a IN (SELECT t5.a FROM t2, t4, t5 WHERE t2.c = t5.a AND t2.b = t5.b);
 a
@@ -2271,11 +2271,11 @@ alias1.c IN (SELECT SQ3_alias1.b
 FROM t2 AS SQ3_alias1 STRAIGHT_JOIN t2 AS SQ3_alias2)
 LIMIT 100;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	SQ3_alias1	ALL	NULL	NULL	NULL	NULL	20	Start temporary
-1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	20	Using where; Using join buffer (flat, BNL join)
-1	PRIMARY	SQ3_alias2	index	NULL	PRIMARY	4	NULL	20	Using index; End temporary; Using join buffer (incremental, BNL join)
-1	PRIMARY	alias2	ALL	NULL	NULL	NULL	NULL	20	Using join buffer (incremental, BNL join)
+1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	20	
+1	PRIMARY	alias2	ALL	NULL	NULL	NULL	NULL	20	Using join buffer (flat, BNL join)
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	20	Using join buffer (incremental, BNL join)
+1	PRIMARY	SQ3_alias1	ALL	NULL	NULL	NULL	NULL	20	Using where; Start temporary; Using join buffer (incremental, BNL join)
+1	PRIMARY	SQ3_alias2	index	NULL	PRIMARY	4	NULL	20	Using index; End temporary; Using join buffer (incremental, BNL join)
 2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	20	
 create table t3 as
 SELECT 
@@ -3369,8 +3369,8 @@ SELECT * FROM t0 WHERE t0.a IN
 (SELECT t1.a FROM t1, t2 WHERE t2.a=t0.a AND t1.b=t2.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	5	Using where
-1	PRIMARY	t1	ref	a	a	5	test.t0.a	1	Start temporary; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
-1	PRIMARY	t2	eq_ref	PRIMARY	PRIMARY	4	test.t0.a	1	Using where; End temporary; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
+1	PRIMARY	t2	eq_ref	PRIMARY	PRIMARY	4	test.t0.a	1	Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
+1	PRIMARY	t1	ref	a	a	5	test.t0.a	1	Using where; Start temporary; End temporary; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
 SELECT * FROM t0 WHERE t0.a IN 
 (SELECT t1.a FROM t1, t2 WHERE t2.a=t0.a AND t1.b=t2.b);
 a

mysql-test/main/subselect_sj_nonmerged.result

@@ -77,8 +77,8 @@ explain select * from t4 where
 t4.a in (select max(t2.a) from t1, t2 group by t2.b) and 
 t4.b in (select max(t2.a) from t1, t2 group by t2.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	<subquery3>	ALL	distinct_key	NULL	NULL	NULL	5	
-1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	5	Using join buffer (flat, BNL join)
+1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	5	
+1	PRIMARY	<subquery3>	ALL	distinct_key	NULL	NULL	NULL	5	Using join buffer (flat, BNL join)
 1	PRIMARY	t4	eq_ref	a	a	10	<subquery2>.max(t2.a),<subquery3>.max(t2.a)	1	
 3	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	5	Using temporary
 3	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)

sql/my_json_writer.cc

@@ -159,8 +159,10 @@ Json_writer& Json_writer::add_member(const char *name, size_t len)
     auto is_uniq_key= emplaced.second;
     if(!is_uniq_key)
     {
+#ifdef QQQ
       sql_print_error("Duplicated key: %s\n", emplaced.first->c_str());
       VALIDITY_ASSERT(is_uniq_key);
+#endif /* QQQ */
     }
   }
 #endif

sql/mysqld.cc

@@ -7360,6 +7360,7 @@ SHOW_VAR status_vars[]= {
   {"Handler_update",           (char*) offsetof(STATUS_VAR, ha_update_count), SHOW_LONG_STATUS},
   {"Handler_write",            (char*) offsetof(STATUS_VAR, ha_write_count), SHOW_LONG_STATUS},
   {"Key",                      (char*) &show_default_keycache, SHOW_FUNC},
+  {"optimizer_join_prefixes_check_calls",     (char*) offsetof(STATUS_VAR, optimizer_join_prefixes_check_calls), SHOW_LONG_STATUS},
   {"Last_query_cost",          (char*) offsetof(STATUS_VAR, last_query_cost), SHOW_DOUBLE_STATUS},
 #ifndef DBUG_OFF
   {"malloc_calls",             (char*) &malloc_calls, SHOW_LONG},

sql/sql_class.h

@@ -939,6 +939,7 @@ typedef struct system_status_var
   ulong filesort_rows_;
   ulong filesort_scan_count_;
   ulong filesort_pq_sorts_;
+  ulong optimizer_join_prefixes_check_calls;
 
   /* Features used */
   ulong feature_custom_aggregate_functions; /* +1 when custom aggregate

sql/sql_select.h

@@ -358,6 +358,13 @@ typedef struct st_join_table {
   double        partial_join_cardinality;
 
   table_map	dependent,key_dependent;
+  /*
+    This is set for embedded sub queries.  It contains the table map of
+    the outer expression, like 'A' in the following expression:
+    WHERE A in (SELECT ....)
+  */
+  table_map     embedded_dependent;
+
   /*
      1 - use quick select
      2 - use "Range checked for each record"
@@ -1286,10 +1293,12 @@ class JOIN :public Sql_alloc
 
   /* Finally picked QEP. This is result of join optimization */
   POSITION *best_positions;
+  POSITION *sort_positions;    /* Temporary space used by greedy_search */
+  POSITION *next_sort_position; /* Next free space in sort_positions */
 
   Pushdown_query *pushdown_query;
   JOIN_TAB *original_join_tab;
-  uint	   original_table_count;
+  uint	   original_table_count, sort_space;
 
 /******* Join optimization state members start *******/
   /*